There is known from the prior art, particularly from EP Patent No. 0 750 177, a gyrometer formed by a single tuning fork having a base from which there extends a first leg on which excitation electrodes are arranged, and a second leg on which detection electrodes are arranged.
FIG. 1 shows an example tuning fork 1 of the type of those that can be used in a gyrometer. Tuning fork 1 shown in longitudinal cross-section in FIG. 1a mainly comprises a base 2 secured to two legs 3, 4, the assembly being made of a piezoelectric quartz material. As shown in transverse cross-section in FIG. 1b, each leg 3, 4 includes electrodes. Excitation leg 3 includes a first pair of excitation electrodes 5a, 5b connected to each other and to which an alternating electric signal is applied at the resonant frequency of the tuning fork in its main plane corresponding to that of FIG. 1a, and a second pair of excitation electrodes 6a, 6b connected to each other and to which an alternating electric signal is applied in phase opposition to that applied to electrodes 5a and 5b. The application of these alternating electric signals excites and consequently causes legs 3 and 4 of tuning fork 1 to vibrate mechanically in a first plane, as indicated by arrows 9. Detection leg 4 includes a first pair of detection electrodes 7a, 7b connected to each other and a second pair of detection electrodes 8a, 8b connected to each other, such pairs converting the mechanical vibrations of the detection leg into an electric signal detected by means of a detection circuit to which said electrodes are connected.
According to tuning fork gyrometer theory, while an excitation signal is being applied to excitation electrodes 5a–5bn, 6a–6b, an angular rotational movement of tuning fork 1 about its longitudinal axis 10 generates a Coriolis force perpendicular to the velocity of the excited leg and to rotational axis 10, and consequently, a vibration in detection leg 4 in a perpendicular plane to the excitation vibration plane, as indicated by arrows 11. This mechanical vibration is converted by the piezoelectric quartz of tuning fork 1 into an electric signal which is detected by the tuning fork detection electrodes 7a–7b, 8a–8b. 
One of the main problems observed with this detection electrode arrangement lies in the fact that the electrical path of the field to be detected between two detection electrodes to which an opposite electrical signal is applied, is not rectilinear, and consequently a non-negligible part of the field lines is lost. Consequently, the detection measurement is not optimal.
A theoretically interesting solution would consist in arranging the two pairs of detection electrodes 7a–7b, 8a–8b, as is shown in FIG. 1c. However, this solution has a major drawback, insofar as it requires implementation of a complex manufacturing method that is difficult to control. Indeed, the electrodes present on the lateral faces of the tuning fork are made by an “electrode deposition”, which is necessarily carried out over the entire thickness of the lateral face. Thus, it is then very difficult to separate the electrode deposition in two, in order to obtain the two desired distinct electrodes 7b, 8b. Moreover, this type of gyrometer is made in series, i.e. one beside the other. Thus, it is also very difficult to separate the electrode deposition made on the external lateral faces of the tuning fork into two distinct electrodes 7a, 8a. 
Moreover, the various aforementioned solutions have an additional drawback, namely the size of the tuning fork, which for such on board gyrometer applications must of course advantageously be as miniature as possible.